What is the issue with the muzzle flash messing with the chrony? How does that work? Does the chrony read the muzzle flash rather than the projectile?

@larda: I dont know exactly what voltage and such I will be using, but my friend works at a computer recycling center, and they have half a million extra caps that we are going to take.

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Do not look back, and grieve over the past, for it is gone;
Do not be troubled about the future, for it has not yet come;
Live life in the present, and make it so beautiful that it will be worth remembering.

Some people here confused thi with a railgun...This is not a railgun. For an amateur project, it surely required less work. A Railgun doesn't work on that principle, it uses and electromagnetic-driven arc to propel a metal-like projectile. What you have here, is more powerful man, it's impressive! I suggest you try adding some more aluminium powder before increasing the electrical power. Big up!

Larda wrote:What dimensions do you think are suitable for my projectile?I was thinking something like 1:50 mass ratio.

Well, the arm length is also important, and an educated guess at a velocity would also help decide on suitable dimensions. Still, it's quite a task to build a really good pendulum, and then you need to fiddle with all kinds of different maths.

So although you can get good results, it might be best to try sound recording first.

I once touched a half charged 300V capacitor, felt as though it nearly blew my hand off. Id be too nervous to even go near your bank, just in case some sort of Darth Sidious reminiscent lightning bolt snaps up to me.

Those are incredible wires, incredible switch, bloody hell. This is incredible, what sort of distance do you reckon it could launch your projectile to? I respect that you probably cant see it through the muzzle "flash" (one heck of a "flash") and it may be too small too find.

I just tried to measure the velocity of the projectile with a ballistic pendulum ,and i think i would have worked fine if the projectile didn't just went right threw the pendulum. First i just thought that i got a bad shoot, but then i saw that it was two holes i the pendulum and a big hols in the wood i used as a bullet trap behind the pendulum.So the projectile just made a hole in the paint bucket i used as a pendulum with over 100mm of wooden planks and 3 pieces of sheet metal.Then threw 3 more 20mm planks and made a big dent in a 6mm stainless steel plate.I will upload a video and some damage Pict's later.

If I wasn't banned from having a bank that large, I'd have to make this.

Umm... Why are you banned from having a bank that large?

@Larda: What kind of armor do you have on the pendulum now? High speed tool steel should work unless you're using carbide projectiles. That's some really impressive power you've got there, for the size of it. If not for the fact that I don't have any hookups to acquire massive cap banks, I'd already be building one of these.

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Spudfiles' resident expert on all things that sail through the air at improbable speeds, trailing an incandescent wake of ionized air, dissociated polymers and metal oxides.

Holy bejeesus!!!I knew there was a lot of power potential in electrothermal cannons, but... bloody hell. I thought what it did to the bricks was a lot, but having heard all of this, my jaw has actually dropped through the floor.

You know DYI, you might have seen that supersonic plasma powered cannon you wanted to. With power like that from a 12mm barrel, this may well be supersonic.

I can tell you, I want one. Pity that's far too much energy for me to safely use where I launch.

windshrike wrote:I second adding more aluminum powder.

More might not actually help. Too much might actually lose power.

Remember, the energy actually comes from the capacitor bank, not the aluminium itself, and the aim is to convert that to plasma as efficiently as possible, for which there will be an optimal quantity.